I am wondering if bike tires have a weight limit. I have to admit, I am a large guy at 6'3" 250lb (190 cm, 113,5 kg), and I have always had issues with my road bike's tires getting pinch flats. I could never seem to put enough air in the tire to keep the rim off the road on bumps, etc. I ride a mountain bike now and I haven't had the same issues. Though of course they are a lot knobbier/thicker.

6 Answers
6

Pinch flats are due to under-inflation of tires. On a road bike you should be inflating your tires to 120-130 lbs.

Also, you need to check and re-inflate your tires every time you ride. I just keep my pump right next to my bike, and wind up adding air every 2nd or 3rd day.

I see you added tire size - those are older bike tires, they don't inflate as high as road bike tires, I'd try pumping them to 65 lbs, and if you are still getting pinch flats, go up 5 lbs at a time until it stops.

You can tell a pinch flat because it will look like a snake bit, 2 small holes close together.

If you do not get any pinch flats at 65 lbs, you can try going down 5 lbs at a time until they return, then you know the range your tires need to be at to be properly inflated.

The most important thing is to check tire pressure every time you ride, as bike tires can lose up to 5/lbs a week from just sitting. These are high pressure tires, so they lose air much faster than low pressure car tires.

Top off your tires and do a 'flight' check every time you ride.
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42-17Aug 25 '10 at 22:39

1

Watching for the bulge around the ground-contact area while you are riding is a very useful way to avoid pinch-flats. If you get only a very very slight bulge, then the tire pressure is most probably right for your weight (provided the tire is not inflated above the maximum allowed on the sidewall).
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heltonbikerMar 30 '12 at 20:32

2

This issue was definitely because of under-inflation. All I had at the time was a hand pump and there was no way I was going to get it up to the proper psi. Got a floor pump and I am much happier now. Thanks for the answer!
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LoganGoesPlacesAug 15 '12 at 12:42

I'm just a tiny bit smaller than you (~10 pounds lighter, depending on what I've eaten that week) and have ridden 700x25 tires/32 spoke rims with no problem. Granted, I keep my tire pressure high, and go over curbs like I'm carrying a baby inside a priceless ming vase, but still.

I raced 5 Ironman races (so 112 Mile / 180 Km) bike segments and did training for that for 5 years. I raced at 235 lbs and now I am riding 30 miles to work at 270 lbs (alas!) and I do not have an issue with pinch flats.

My road tires I run at 120 lbs or so of pressure. Though with the recent hot weather my pump was not getting the pressure that high due to over heating.

@RitchMelton 700c at 25 or 28mm width. So normal road tires. Usually something with kevlar reinforcement along the bottom for puncture resistance. I was all Vitorrio Rubinos (Had a good source for cheap tires, but finally used up the last one) and now mostly switched to Bontragers, whose model I forget off hand.
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geoffcJun 28 '13 at 20:31

You didn't tell us at what pressure did you inflate your tires and that's a important thing when it comes to pinching the tire.

Road bike tires can be easily inflated up to 7-8 bars (100-115 psi) and for your weight, I think this would be enough to protect your tire.

I ride a trekking bike and inflate the tires to 4.5 bars (65psi), similar weight as you and I don't have problems with pinched tires. Granted, the tire dimension is bigger, but the pressure is also half of what the road tire would have.

My girlfriend and I inflate the tires on our touring tandem to 90 psi. The bike carries both of us plus two fully loaded panniers in the back. At 90 psi in the tire with what probably ends up being over 350 lbs on the bike, we have never had a pinch flat. That said, I drive the bike very carefully to avoid hitting anything with a sharp edge (lots of driveways have a nasty edge on them). I wouldn't recommend over-inflating your tires (they're rated for a reason), but if you're getting a lot of pinch flats, you might consider riding a little more conservatively. A little caution can go a long way toward making things last.

out of naive curiosity, why not ride a wider tire? I'm ~220 riding 25c tubulars at 110/125 psi. That value feels pretty good to me and I was surprised to read that your pressure was about the same. So much of finding a proper tire pressure seems anecdotal.
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Ritch MeltonJun 28 '13 at 14:59